I replaced my TP with an Evo for free.
Long story though, and not very repeatable. About one month before the Evo release, my TP took a crap. I had BB's Geek Squad protection plan on it, so I turned it in to them and they gave me a loaner phone to use while my phone was in repair.
First thing I noticed about the loaner phone is that it had all of the previous user's data still on it. Yikes! I emailed the BB manager to complain about this, and he offered me a $50 gift card and assurance that data security procedures would be followed more strictly in the future.
A month later, my phone was still in repair (Geek Squad is
really slow), and I got a call in that an Evo was waiting for me. This was about two weeks after launch, in the second batch of shipments (no preorder). So I went in expecting to pay $200 - I was eligible for upgrade. The BB Mobile guy asked me where my old phone was, and I said it was at Geek Squad waiting for repair.
He and the manager then spent a long time working a bunch of magic, and when it was all done, my total for the Evo came to $40. He explained it like this: my TP had just been "junked-out" (deemed unrepairable), so I got a store credit for the nearest equivalent, which was the Hero. So I only had to pay the difference in price between the Hero and Evo. Using the $50 gift card from the loaner phone debacle, this means I got upgraded to the Evo for free. My receipt is about five feet long, but I'm happy! It's even an 003 with no issues to report as of yet.